1.

Prove the followings identities:(1 + cos θ)(1 – cos θ) = sin2θ

Answer»

Taking LHS = (1 – cosθ)(1+ cosθ)

Using identity , (a + b) (a – b) = (a2 – b2) , we get

= (1)2 – (cosθ)2

= 1 – cos2 θ

= sin2 θ [∵ cos2 θ + sin2 θ = 1]

= RHS

Hence Proved



Discussion

No Comment Found